Thioglycerol-nitrogen base molecular complex depilatory compositions

ABSTRACT

A thioglycerol-nitrogen base molecular complex useful as a depilatory; complexes are unimolecular or hemimolecular.

United States Patent Yablonsky [54] THIOGLYCEROL-NITROGEN BASE MOLECULAR COMPLEX DEPILATORY COMPOSITIONS Harvey A. Yablonsky, Elizabeth, NJ.

Assignee: Bristol-Myers Company, New York,

[72] Inventor:

Filed: April 2, 1969 Appl. No.: 812,903

References Cited UNITED STATES PATENTS 6/1944 Evans et al. .L ..8/161 51 Aug. 22, 1972 FOREIGN PATENTS OR APPLlCATlONS 636,181 4/ 1950 Great Britain 593,438 10/ 1947 Great Britain OTHER PUBLICATIONS Technical Notes, Agricultural Research Service, 1968, Jones et al.

Primary Examiner-Lewis Gotts Assistant ExaminerJohn F. Terapane Att0rney--William F. Moss, 111, David J. Mugford, Irving Holtzman, George A. Mentis and Ralph D. Gelling [57] ABSTRACT A thloglycerol-nitrogen base molecular complex useful as a depilatory; complexes are unimolecular or hemimolecular.

2 Claims, No Drawings THIOGLYCEROL-NITROGEN BASE MOLECULAR COMPLEX DEPILATORY COMPOSITIONS This invention relates to depilatory compositions. More particularly, it concerns depilatory compositions wherein the active depilating agent is a molecular complex of thioglycerol and a nitrogen base.

A variety of organomercapto compounds have been suggested for use in the prior art as depilatories. These, however, leave much to be desired with regard to the speed with which they remove hair at pHs which are tolerable to the skin, e.g., pH 8.5 to 10.5. Thus, for example, British Pat. No. 636,181 proposes, as depilatories, mercapto carboxylic acids in conjunction with enough free organic base to make the solution alkaline. This composition lacks much with respect to the rate at which the hair may be safely removed from the skin.

British Pat. No. 593,438 concerns a depilatory composition which comprises a combination of thioglycerol with certain inorganic bases, such as the hydroxides of the alkali metal or the alkaline earth metals. Again, the inorganic base is merely added in sufiicient quantity to establish a certain alkaline pH. This too leaves much to be desired regarding the rate at which the hair may be safely removed.

It has now been found that molecular complexes formed between nitrogen bases and thioglycerol in which the molar ratio of nitrogen base to thioglycerol or thioglycerol to nitrogen base is 1:1 or 120.5 are highly efficient depilatory agents. These are particularly effective in aqueous compositions which have a pH in the range of 8.5 to 10.5.

It is, accordingly, an object of the present invention to provide depilatory compositions which are highly efficient in rapidly removing hair from skin, said compositions being most effective in the pH range of 8.5 to 10.5.

It is also an object of the present invention to provide depilatory compositions of the type mentioned in the above object in which the active depilatory agent is a molecular complex of a nitrogen base and thioglycerol.

Other and more detailed objects of this invention will be apparent from the following description and claims.

As noted above, the active depilatories of the present invention are nitrogen base-thioglycerol molecular complexes. These complexes may be expressed generically by the formulas selected from the group consisting of:

A [HSCH2CHOHCH2OH],, 1

[A]- [HSCl-I CHOHCl-l OHL, n in which A is a nitrogen base and the ratio a/b, i.e., the molar of nitrogen base to thioglycerol or thioglycerol to nitrogen base is l or 0.5.

The stoichiometry of these complexes vary with the nitrogen base selected. It has been determined in a manner known in the prior art, throughstudies of the fluidities of aqueous solutions containing the materials as a function of mole fractions of the nitrogen base. See the following authorities:

Dunstan and Thole, VISCOSITY OF LIQUIDS, Page 44 (London, 1917). Faust, 0., ZEIT. PHYSIK. CHEM., 79 (97) 1912. Hatschek, Emil, THE VISCOSITY OF LIQUIDS,

Page 142, G. Bell and Sons, London, 1928. Kurnakow, N., and Shemtchushni, S.,

PHYSIK.Cl-1EM., 83, 481, 1913.

ZEIT.

Kumakow, N., ZEIT. ANORG. CHEM., 135, 81

The fluidities of the solutions were determined at 30 C. using both the Ostwald viscosimeter and the falling sphere method, the latter being more convenient due to the high viscosity of the solutions.

The stoichiometry of the present complexes determined in this manner was shown to be either equi or hemi molar. The alkyl amine complexes are examples of the former, whereas the alkanol amine complexes are examples of the latter. This stoichiometry is also reflected in the activity of compositions containing thioglycerol and employing varying amounts of nitrogen base. It has been found that the presence of the nitrogen base generally enhances the depilatory activity of the particular thio compound. However, nitrogen base concentration in excess of that necessary for complete complex formation does not increase the depilation activity above the completely complexed thio mixture. On the other hand, when the concentration of the nitrogen base is below that necessary for complete complexing of the thio compound, the depilation activity is appreciably diminished.

A screening method has been developed for quantitatively evaluating the depilatory activity of a composition. This is based on the observation that human hair undergoes a characteristic form of swelling in many depilating solutions. This swelling may be reduced to two sequential events:

a. cross sectional swelling and b. longitudinal swelling. Both of these swellings when plotted against time produce a sigmoid curve. The sigmoid character is, however, more clearly defined in the case of the longitudinal component. This has, accordingly, been adopted for measurement of the depilatory activity.

The measurement T the time period at which the maximum rate of longitudinal swelling is initiated, is taken as a quantitative indication of the effectiveness of a depilating solution. A preparation possessing a T value of 3 minutes is capable of completely depilating a rabbits belly in less than a minute. A number of wellknown commercial depilatory preparations for human skin have T values in the range of about 25 minutes. It has been found that while the hair remains intact, the T value may for all intents and purposes be considered independent of the cuticle conditions.

The fact that the nitrogen bases of this invention do not merely serve to render the final compositions alkaline, is shown by the following observation:

Two aqueous solutions were prepared, one utilizing merely sufficient nitrogen base (i.e., methylamine) to bring the hydrogen ion concentration to the desired low level (pl-I 10). A second aqueous solution was prepared with sufficient of said nitrogen base to completely complex the compound employed, i.e., thioglycerol in the molar ratio of lMzlM. Hydrochloric acid was then added to the latter solution to increase its hydrogen ion concentration and bring it to the same level as the first solution. The depilating activity of each of the solutions were determined as measured by the T value. The first solution had a value of 6-7, whereas the second solution had a value of 1.5-2; showing an appreciably greater depilatory activity in solution two containing a complex of the present invention.

Any of a large number of nitrogen bases and mixtures thereof may be employed in preparing the complexes of this invention. However, the ease of complex formation increases with the increase of the K, of the nitrogen base. This is also correlated with the increase in depilatory activity of the product if the evaluation is carried out in the desired pH range, i.e., 8.5 to 10.5. Generally, it may be stated that nitrogen bases having a K, in the range of about 10' to l are quite suitable for the present purposes.

The nitrogen bases which have been found to be advantageous in this invention vary quite widely structurally and include such lower alkyl amine (one to six carbon atoms) as methylamine, dimethylamine, ethylamine, isopropyl amine, di-isopropyl amine, di-npropyl amine, methyl isopropyl amine, dimethyl isopropyl amine, acetarnidine, cyclohexyl methyl amine, isobutyl amine, tert. butyl amino cyclohexane; and such lower alkanol amines (one to six carbon atoms) as monoethanolamine, triethanolamines, 6 hydroxy-n hexylamine, 4 hydroxy-n butylamine, 5 hydroxy-l-pentylamine; urea, heterocyclic nitrogen bases such as imidazole, 1,2dimethyl-2 pyrroline, piperidine, quinuclidine, pyrrolidine, 2 cyclohexyl pyrrolidine, pyrroline guanidine and guanidine hydrochloride, etc.

Another class of nitrogen bases that are especially useful for the present invention is sold under the trade designation DERIPHAT. These are described by the formulas:

RCH,NHCH CH COOM ill and RCH,N(CH,CH COOM), iV wherein M is a salt-forming cation (e.g., Na or H) and R is the hydrocarbon moiety of the long-chain fatty acid RCOOH, e. g., (C, to C and preferably C to C fatty acids. These include sodium N-coco-B- aminopropionate (DERIPHAT 151); N-coco-B-amino propionic acid (DERIPHAT 151C); N-lauryl, myristylout in Tables II and Ill below.

TABLE II fi w a R-C-N-CHCHO CHzC 0 OM| CHzC O 0M2 RCOOH which serves R as source for R M1 M2 Trade designation 0111123.... Coconut oil acids Na Na Miranol 02M cone. .CnHz: do H H Mlranol CZM-SF cone.

as caprylic and $1; Na Na Miranol J EM concethylhexoie. C1Hn.. Caprylic Na Na Miranol J 2M cone. O1 Ha| Linoleic Na Na Miranoi LZM-SF cone.

TABLE III /CE2 N (EH2 R- -N"CHzCH|0M1 (I) CHBOOOMB RCOOH which serves R as source for R M1 M1 Trade designation Na Miranol HM cone. Na Miranol OM-SF cone. Na Miranol SM cone. Na Miranol DM.

B-amino propionic acid (DERIPHAT 170C); disodium N-tallow-B-iminopropionate (DERIPHAT 1 4); disodium N-lauryl-B-iminopropionate (DERIPI-IAT 160) and the partial sodium salt of N-lauryl-fiiminopropionic acid. These are particularly .suitable because of the extremely low order of mercaptan odor exhibited by complexes made from these bases, an odor which is a drawback'in many commercial products.

Still another class of nitrogen bases that is suitable for the present purposes is sold under 'the trade designation Miranol. These are defined by the general formula:

a. R is the hydrocarbon moiety of the long-chain b. R, is H, Na or CH,COOM; c. M is Na, H or an organic base and d. G is OH, an acid salt or the salt of an anionic surface active sulfate or sulfonate. These are described in US. Pats. Nos. 2,528,378, 2,773,068 and 2,781,354. Specific compounds of this character that can be employed in this invention are set A further class of nitrogen bases that has been found to be useful in preparing the complexes of the present invention is marketed under the trade designation MONATERICS. These are substituted imidazolines of formula:

VIII HzC--N a ll H, CR

\ N HrCHgO-CHzCHrCOOH wherein R is a long-chain hydrocarbon moiety (e.g.,

C -C and preferably C -C derived the fatty acid RCOOH. Particular compounds of this character that are employed herein are given in Table IV below.

In using the molecular complexes of the present invention as depilatories it is highly desirable to incorporate them in an aqueous base. The amount of water contained in these aqueous compositions can vary; In

general, the water will constitute between about 20 to 80 percent by weight of the total finished product.

The natural pH of the complexes formed between the nitrogen bases and the thioglycerol will vary depending upon the nitrogen base selected or the relative amounts of the respective components of the complex. The most effective pH range for depilating with the present complexes is pH 8.5 to 10.5. Where the natural pH is too low, it may be increased by using any suitable base. Methylamine has been found to be especially suitable for this purpose although other bases, e.g., NaOH may also be employed. Similarly, where the natural pH of the complex is too high, e.g., above 10.5, it may be brought into the proper range with an acid. Hydrochloric acid has been used to advantage for this purpose.

The amount of the thioglycerol-nitrogen base complex contained in a composition relative to the total weight of the composition will vary depending on the vention may be incorporated in a variety of carriers and may be employed for a variety of purposes. Thus, for example, they can be employed in simple aqueous solutions or be incorporated in a cream base or a gel. .These may be employed for a variety of purposes, some of which are mentioned below:

a. fast acting depilatory (wipe on, wipe off);

b. self-neutralizing permanent waving solution;

c. hair straightener (anti-kinking solution);

d. non-gum, non-grease mens hair groom;

e. shaving cream which will appreciably condition hair and facilitate shaving;

f. mens pre-shave lotion.

In using the compositions of the present invention as depilatories, procedures well known to those skilled in the art are employed. The compositions are applied to areas of skin from which the hair is to be removed. This is allowed to remain in contact with the hair for no more than about 4 minutes after which it is wiped off taking off the hair.

The following examples are further illustrative of the present invention. It is to be understood, however, that the invention is not limited thereto.

EXAMPLE 1 An aqueous solution was prepared containing 1.0 M

prepared in Example 1. The corresponding data is given for each composition TABLE IV Concen. Nitrogen pH and agent Ex. of Thio- Base and used to adjust No. Glycerol Concentration the pH T 2 0.75 M imidazole 10.0 2.0

' 1.5 M (methylamine) l.0 M imidazole 9.5

0.5 M (NaOH) 4 1.0 M imidazole 10.0 4.5-

0.5 (methylamine) 5.0 5 1.0 M imidazole 9.0 5-6 2.0 M (methylamine) 6 2.0 M imidazole 8.75 6-7 4.0 7 1.0 methylamine 10.0 2-

2.0 M 2.5 imidazole 0.5 M 8 L0 M ethylamine l0.0 4.0

1.0 M (NaOH 9 1.0 M Na-N-coco- 9.5 3.75

aminopropionate (Deriphat 151C) 1.0M 10 [.0 M N-coco-amino- 10.0 2.50

propionic acid (Deriphat 151C) 1.0 M ll l.0 M Deriphat 151C 10.0 3-4 0.5 (methylamine) l2 1.0 M Deriphat 151C 9.5 2-3 1.0 M (methylamine) 13 1.0 M Deriphat l5lC 10.0 4-

2.0 M (methylamine) 4.5 14 1.0 M Monateric LA 9.5 3.70

0.5 M 15 1.0 M Monateric LA 9.5 6-7 1.0 M (methylamine) 16 1.0 M Monateric LA 9.5 3-

2.0 M (methylamine) 3.5 17 1.0 M Miranol C2M 9.5 4-

SF (methylamine) 4.5 0.5 M 18 1.0 M Miranol C2M 10.0 3.5-

SF (methylamine) 4.0 0.5 19 1.0 M Miranol C2M 9.5 6-7 SF (methylamine) 1.0 M 20 2.0 M urea 10.0 4-5 4.0 M (NaOH) 21 0.5 M urea 9.0 12- l.0 M (NaOH) 14 22 1.0M urea 10.0 4-5 2.0 (NaOH) M 23 0.5 M dimethylamine 11.5 4-5 1.0 M 24 1.0 M dimethylamine 9.5 8-9 2.0 M (l-lCl) 25 2.0 M dimethylamine 10- 4.0 M 12 26 0.5 M methylamine 11.5 5- 6 1.0 M 27 1.0 M methylamine 10.0 1.5-

1.0 M 2 28 1.0 M methylamine 10.0 2.5-

2.0 M (HCI) 3.5 29 1.0 M methylamine 9. 3.5- 2.0 M (HCI) 4.0 30 0.5 M monoethanolamine 6-7 1:0 M 31 1.0 M monoethanolamine 9.75 6-7 1.0 M 32 1.0 M monoethanolamine 10.0 4.5-

2.0 M 5 33 2.0 M monoethanolamine 9.25 5-6 In Example 1 through 33 above, water is used as the vehicle. However, in each case aqueous alcoholic solutions may be used as the solvent for the complex. Methanol-water mixtures containing up to 50 percent by volume of methanol may be used in place of the water. When ethanol is employed it may constitute up to about 25 percent by volume of the aqueous alcoholic vehicle.

The following Examples illustrate compositions of the present invention employing gels or cream bases as the vehicle for the thioglycerol-nitrogen base complex.

EXAMPLE 34 thioglycerol 1.0M Na-N-coco-fi-aminopropionate 1.0M lauryldimethylarnine oxide 10% by wt.

This product has a natural pH of 9.5 and is in the form of a gel. It had a T value of from about 2.0 2.5.

EXAMPLE 35 A cream base was prepared containing the following ingredients in by weight:

Cream Base isopropyl palmitate 4.0 hexachlorophene 0.5 glycerylmonosterate 3.0 merthiolate 0.005 water to 100% Using this base as a solvent, a composition was prepared containing thioglyercol and MIRANOL C2M-SF (See Table II above) in concentrations of 1M respectively. The pH of this composition was adjusted to 9.5 with NaOH. The composition had a T value of 4.0 4.4.

EXAMPLE 36 EXAMPLE 37 A slurry was prepared from hydroxypropyl methylcellulose (4,000 CPS) and water containing said cellulose derivative and water in the ratio of l :4 by volume. Using this slurry as a solvent, a composition was prepared containing thioglycerol and methyl amine in concentrations of 1M respectively. This had a natural Ph of about 10 and a T value of 2 2.5.

Although the invention has been described with reference to specific forms thereof, it will be understood that many changes and modifications may be made without departing from the spirit of this invention.

What is claimed is:

l. A nitrogen base-thioglycerol molecular complex having a formula selected by the group consisting of:

[A] [HSCH CHOHCH OHh and [A], [HSCH CHOHCH OHL in which A is nitrogen base and the molar ration of a/b is 1 or 0.5; wherein the nitrogen base has a K value in the range of from 10- to l0" and wherein the nitrogen base is selected from the group consisting of RCH NHCH CH COOM and RCH N(Cl-l H COOM) in which M is H or sodium or an organic base and R is a long-chain aliphatic hydrocarbon moiety of the fatty acid RCOOH.

2. A complex according to claim 1 wherein the nitrogen base is Na-N-coco-Baminopropionic acid. 

2. A complex according to claim 1 wherein the nitrogen base is Na-N-coco- Beta -aminopropionic acid. 